Why is the texture appearing different, and then not rendering?
To use any image with transparency (alpha channel) in cycles you need three nodes. Typically a Transparent BSDF, a Diffuse BSDF (or some other color shader) and a Mix Shader.  

Here is the most basic node setup for a transparent image texture in cycles.


However that is not what you want, if you use that setup you will end up with you guy's head being see through.

Now the principal is simple, you treat the color data and alpha data differently.
The color data gets displayed, but the alpha gets used as a mask. What it is masking is totaly up to you and your specific nodes.
In my nodes, in the image above, I'm making the alpha completely transparent, with the Transparent BSDF.
However for you, you can use your base color instead of a transparent node.

Here is an example showing the difference between using a diffuse node (left side) and a transparent node (right side) as the base under the image texture.